JOURNAL OF MICROSCOPICAL SCIENCE. 

DESCRIPTION OF PLATES VII, VIII, 
Illustrating Dr. Greville’s paper on Diatomacez in 
Californian Guano. 
PLATE VII. 
Fig. 
1.—Cocconeis regalis.* 
2.—Aulacodiscus Oreganus. 
3.—Campylodiscus stellatus. 
4.—Asteromphalus flabellatus ? with straight rays. 
5.—The same? with the hyaline area nearly centrical and the rays straight. 
6.—Asteromphalus elegans. 
7.—Spatangidum Ralfsianum, very large ; the hyaline area nearly centrical, 
and the rays nearly straight. 
3.—The same ; typical in its characters. 
PLATE VIII. 
9.—Achnanthes angustata. 
10.— Biddulphia longicruris. 
1l.— Y Roperiana ; side view. 
12.—The same; front view. 
13.—The same ; front view, approaching self-division. 
14.— Cresswellia turgida. 
15.—Cresswellia (?) ferox ; frustules in union. 
16.—The same ; a valve seen vertically. 
The figures are x 400 diameters. 
* Since this paper was written I have seen a species much resembling this, 
in guano from Algoa Bay, in which I find it had also been previously 
detected by several friends. It has been suggested that it may be only the 
sporangial state of Cocconeis Grevillit. It remains to be seen, however, 
whether it be really identical with the one I have figured. The view of the 
upper valve from within has not occurred to me in Californian guano ; nor 
the view represented in the plate, in Algoa Bay guano. 
